US3244945A

US3244945A - Externally adjustable voltage regulator having permanent magnet control

Info

Publication number: US3244945A
Application number: US290655A
Authority: US
Inventors: Allen E Beaty
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1963-06-26
Filing date: 1963-06-26
Publication date: 1966-04-05
Anticipated expiration: 1983-04-05

Description

Aprll 5, 1966 A. E. BEATY EXTERNALLY ADJUSTABLE VOLTAGE REGULATOR HAVING PERMANENT MAGNET CONTROL Flled June 26 1965 PERMANENT MA GNET INVENTOR. ALLEN E BEATY BY QW A TTOR/VE United States Patent Office 3,244,945 Patented Apr. 5, 1966 EXTERNALLY ADJUSTABLE VOLTAGE REG- ULATOR HAVING PERMANENT MAGNET CONTROL Allen E. Beaty, Anderson, llnd., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed June 26, 1963, Ser. No. 290,655 4 Claims. (Cl. 317172) This invention relates to voltage regulators and more particularly to a voltage regulator which has an external adjustment means for adjusting the amount of voltage required to move the armature of a voltage regulating relay.

In voltage regulators of the vibrating contact type, it is at times necessary to remove the cover of the regulator in order to adjust the spring tension which biases the armature of the voltage regulating relay in one direction. This adjustment is required in order to adjust the output voltage of a generator which is being regulated by the voltage regulator. p

The present invention in contrast to an arrangement wherein the regulator cover must be removed to adjust the voltage regulating relay is concerned with a means for externally adjusting the voltage regulating relay without the necessity of removing the cover.

External adjustment for voltage regulating relays has been accomplished in the past by devices which require the shifting of a conductive screw between different positions to regulate a tapped type of resistor. Another method is illustrated in the patent to Heath, 2,869,051, in which a flux shunting device can be externally adjusted to adjust the voltage regulator.

In contrast to the device shown in the Heath patent and in contrast to external adjustment devices which require the shifting of a conductive screw, it is an object of this invention to provide an adjustment device for an electromagnetic relay which includes a permanent magnet that can be shifted to aid or oppose the flux flowing between the core of the electromagnet and the armature.

Another object of this invention is to provide :an adjustment device for a relay wherein a permanent magnet is rotatably supported by the cover of the relay and is located in such a position that the flux traversing the air gap between the core of the relay and the armature can be aided or opposedby the flux of the permanent magnet. With this arrangement, it is possible to replace existing covers on regulating relays with a new cover which has the rotatable permanent magnet to provide an external adjustment means for an existing regulating relay. I

Further objects and advantages of the present invention will be apparent from the following description, reference being bad to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is an end view of a voltage regulating relay having the external adjustment means of this invention.

FIGURE 2 is an enlarged sectional view taken along line 22 of FIGURE 1.

FIGURE 3 is a view taken along line 33 of FIG- URE 2.

FIGURE 4 is a perspective view showing the relative positions of the permanent magnet and the regulating relay.

Referring now to the drawings, the reference numeral generally designates a base of a conventional voltage regulating relay. This relay may be of a so-called double contact type which is shown in the patent to Heath, 2,920,160. The relay includes the usual magnetic core (not illustrated) which is attached to a pole piece 12 formed of magnetic material and which is secured to the base 10 as by a rivet 14. The core is surrounded by a conventional c-oil winding 16. The rivet 14 serves to hold a U-shaped member 18 in place which is sometimes termed as the heel-iron of the relay.

The armature for the relay is generally designated by reference numeral 20. This armature includes the part 22 which is pivotally secured to one end of the leg 18a of the frame 18 by a conventional flat spring hinge 24. The magnetic part 22 carries an electrical contact 26 which cooperates with a fixed contact 28 carried by a spring arm 30. The end of the arm (not shown) in FIG- URE 2 can be supported by the base of the relay and this arm 30 carries another fixed contact 32. The arm 30 which carries the

fixed contacts

28 and 32 can be adjusted vertically by rotating a plastic part 34 which is threaded on to a screw 36 carried by the leg 18b of the relay frame 18. It will be appreciated that the

contacts

26 and 28 open and close as the armature 20 is moved.

The armature 20 carries another metal part 38 which is engaged by one end of a spring 39 to urge the armature 20 upwardly in FIGURE 4. The part 38 carries a contact 40 which cooperates with the fixed contact 32. The part 38 is insulated from the part 22 by the

insulators

42 and 44.

When the coil winding 16 is energized, flux is generated in the core of the coil winding and flux can flow through the core, through the frame 18, :then through the portion 22 of the armature and then across the air gap to the pole piece 12 and back to the opposite side of the core for the coil winding, This flux tends to cause the part 22 of the armature to move toward the pole piece 12 in a manner well known to those skilled in the art and this movement is opposed by the spring 39.

The present invention is concerned with an external adjustment means for aiding or opposing the flux transversing the air gap between the part 22 of the armature and the top of pole piece 12. To this end, the cover 50 of the voltage regulator is provided with a permanent magnet 52 which is formed to provide

arcuate segments

54 and 56. The permanent magnet 52 can be of the ferrite type and is magnetized, for example, such that the arcuate segment 54 is a north pole and the arcuate segment 56 is a south pole.

The permanent magnet 52 is adjusted by moving a knob 58 which is formed, for example, of plastic material. The knob 58 has an axially projecting section 60 which passes through an opening in the permanent magnet 52. The knob SS engages a plastic part or rotatable support 62 fitted in an opening formed in the cover 50 having a detent projection 64 which can snap into depressions 66 formed in the cover 50. The permanent magnet is held in place by a-spring clip 68 having

tang sections

68a and 68b which grip the portion 60 of the knob 58 when the spring clip is pushed on to the portion 60. The spring clip fits within slots 70 formed in the permanent magnet that separate the

arcuate sections

54 and 56 and the spring clip therefore serves to hold the permanent magnet in place and also to rotatably drive the permanent magnet. The spring clip 68 is also located within slots 72 formed in the plastic part 62 so that the spring clip rotatably drives the plastic part 62. The detent projection 64 can snap into the depressions 66 of the cover 50 as it is rotated.

Although a specific means has been disclosed for sup porting and rotatably driving the rotatable magnet, it will be appreciated that various other means could be provided to accomplish the same purpose.

In order to understand the function of the permanent magnet 52, it will be appreciated that the amount of pull applied to the part 22 of the armature 20 will depend upon the amount of flux traversing the air gap between the pole piece 12 and the part 22 of the armature. This flux can be aided or opposed in a varying magnitude by the perma- I nent magnet 52 which can be rotated to various positions relative to the part 22 and pole piece 12 of the voltage regulating relay. Thus in certain positions, the

arcuate sections

54 and 56 will be in such a position as to add to the flux traversing the air gap between the pole piece 12 and the armature part 22. In other positions, the flux provided by the permanent magnet 22 may still be additive but due to its relative position will have less effect. The permanent magnet can be adjusted such that its

arcuate sections

54 and 56 will oppose the magnetic flux traversing the air gap between the pole piece 12 and the armature part 22 and to various degrees of opposition.

Where the permanent magnet aids the magnetic flux provided by the coil winding 16, it will be appreciated that it will require less magnetic flux by the coil winding 16 to move the armature part 22 toward the pole piece 12. On the other hand, where the permanent magnet opposes the magnetic flux traversing the air gap between part 22 and the pole piece 12, it will take a greater magnetic flux generated by the coil winding 16 to pull the armature part downwardly. In this manner, the voltage regulating relay can be externally adjusted to provide the desired output voltage for the generator that it regulates. Thus where the output voltage of the generator is too high, the permanent magnet is adjusted in such a direction as to aid the magnetic flux traversing the air gap between armature part 22 and pole piece 12 and where the generator voltage is too low, the permanent magnet is adjusted to oppose this flux.

While the embodiments of the present invention as herein disclosed constitute a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A relay comprising a coil winding, an armature, a magnetic circuit including an air gap and said armature for flux generated by said coil winding, a cover member for said relay, a rotatable support having a portion fitting within an opening formed in said cover member, said support having a detent means which is adapted to snap into depressions formed in said cover member, an actuating knob having a projecting portion passing through said support, a permanent magnet located Within said cover having a central opening receiving said projecting portion of said actuating knob, and a spring clip for holding said permanent magnet with respect to the projecting portion of said actuating knob, said spring clip fitting, within slots formed in said support and in said permanent magnet, said permanent magnet being located adjacent said air gap to aid or oppose the fiux generated by said coil winding which traverses said air gap.

2. A relay comprising a base, a cover secured to said base, said cover and base defining a compartment, a coil winding in said compartment for generating magnetic flux, an armature located within said compartment shiftable toward said coil winding under the influence of said magnetic flux, and a permanent magnet adjustable relative to and supported by said cover member for aiding or opposing the magnetic flux generated by said coil winding, said permanent magnet being located within said compartment, and means external of said compartment connected with said permanent magnet for adjusting said permanent magnet, said permanent magnet being spaced from said armature and coil winding to provide an air gap between said magnet and said armature and coil winding.

3. An electromagnetic relay comprising a base, a cover secured to said base, said base and cover defining a compartment, a magnetic core located in said compartment, a coil winding wound on said magnetic core, an armature in said compartment, a magnetic circuit for said relay including an air gap located between said core and said armature, and a permanent magnet having a pair of pole faces of opposite magnetic polarity located at one side of said air gap, said permanent magnet being located in said compartment and supported by said cover, said permanent magnet being adjustable to aid or oppose the flux passing through said air gap generated by current flow through said coil Winding, said pole faces being located in a plane which is substantially normal to the plane of said armature, said pole faces being spaced from said core and armature to provide an air gap between said pole faces and said core and armature.

4. In combination, a cover for an electromagnetic relay, an actuating knob located externally of said cover having a section passing through an opening in one wall of said cover, a spring clip fixed to a portion of said actuating knob, and a permanent magnet located within said cover having a slot defined by a pair of side walls extending from a bottom wall, said spring clip being located within said slot and engaging the side walls of said slot for rotatably driving said permanent magnet, said spring clip engaging said bottom Wall of said slot to hold said permanent magnet in place axially relative to said knob.

References Cited by the Examiner UNITED STATES PATENTS 252,497 1 /1882 Mott 317-176 2,321,157 6/1943 Rees -36 2,369,380 2/ 1945 Tinnerman 85-36 X 2,673,263 3/1954 Casey 317-171 X 2,892,187 6/1959 Bredehoft 317-l77 X 2,920,160 1/1960 Heath 20087 2,972,038 2/ 1961 Gomersall 20087 X FOREIGN PATENTS 235,643 9/1961 Australia. 1,258,367 3/1961 France.

JOHN F. BURNS, Primary Examiner. LARAM'IE E. ASKIN, Examiner.

Claims

4. IN COMBINATION, A COVER FOR AN ELECTROMAGNETIC RELAY, AN ACTUATING KNOB LOCATED EXTERNALLY OF SAID COVER HAVING A SECTION PASSING THROUGH AN OPENING IN ONE WALL OF SAID COVER, A SPRING CLIP FIXED TO A POSITION OF SAID ACTUATING KNOB, AND A PERMANENT MAGNET LOCATED WITHIN SAID COVER HAVING A SLOT DEFINED BY A PAIR OF SIDE WALLS EXTENDING FROM A BOTTOM WALL, SAID SPRING CLIP BEING LOCATED WITHIN SAID SLOT AND ENGAGING THE SIDE WALLS OF SAID SLOT FOR ROTATABLY DRIVING SAID PERMANENT MAGNET, SAID SPRING CLIP ENGAGING SAID BOTTOM WALL OF SAID SLOT TO HOLD SAID PERMANENT MAGNET IN PLACE AXIALLY RELATIVE TO SAID KNOB.